E-cigarettes contain nicotine but not the cancer-causing tar present in traditional cigarettes. Nicotine is a highly-addictive drug, and a Thursday report warns it may harm the developing adolescent brain.

“The bottom line is that there is no safe use of tobacco products for kids, and those include e-cigarettes,” Murthy said.

E-cigarette companies have rapidly increased advertising spending, from $6.4 million in 2011 to $115 million in 2014. Regular e-cigarette use among high school students increased from less than 2 percent in 2011 to 16 percent last year.

“What we’ve seen is the vast majority of kids — 7 out of 10 — are actually seeing these advertisements,” Murthy said.

“Whether that’s intentional or unintentional that tells us that we’re not doing a good enough job at protecting kids,” he added.

“We do know that flavors have a powerful impact on kids,” Murthy said. “In fact, 81 percent of kids when asked why they use e-cigarettes cite flavors.”

Murthy says more research is needed on whether e-cigarettes are a gateway to traditional cigarettes. Industry groups are criticizing Thursday’s report because it does not highlight the possible role e-cigarettes may have in helping people stop smoking.